Submarine sampler

ABSTRACT

A flooded bin measurement system is provided that includes a submarine sampler for ascending and descending within a liquid of a bin and for measuring the depth of fluid at the submarine sampler&#39;s location. In one embodiment, the submarine sampler may ascend and descend along a vertical guide based on adjustments to it buoyancy compared with the liquid in the bin, which may be controlled manually and/or automatically. The measurement system may include a bubbler system for measuring hydrostatic pressure at the submarine sampler for determining its depth within the fluid of the bin. The submarine sampler may include a device having a hollow interior, an open bottom and an air supply line connected to the hollow interior. According to a further embodiment of the invention, the submarine sampler may be fixed to a line that is connected to a counterweight at its opposite end.

RELATED APPLICATION

This application is a division of application Ser. No. 11/170,994 filedJun. 29, 2005 now U.S. Pat. No. 7,464,589, which claims the benefit ofU.S. Provisional Application No. 60/583,610 filed Jun. 30, 2004, whichis hereby fully incorporated herein by reference.

FIELD OF THE INVENTION

This invention relates generally to a method for measuring the level ofsolids in a container. More particularly, the invention relates to amethod for measuring the level of solid materials at the bottom of acontainer holding both liquid and solid materials, and to a measurementsystem for performing the same.

BACKGROUND OF THE INVENTION

Containers holding both solid and liquid materials are often used inindustry. Frequently, the solid materials in these containers are denserthan the liquid materials and collect at the bottom of the container. Inmany instances it is desirable to monitor the level of these solidmaterials; however, measuring the depth of solids at the bottom of aflooded bin can be difficult, impractical or inaccurate. One obstaclemay be that the liquid materials are volatile and/or instable, which maymake it unsafe for manual measurements and processes requiring humancontrol. Further, properties of the solid material may prove to be ahindrance to accurate measurements. Yet another obstacle may be thegeometry of the bin.

Measurement systems have been developed to attempt to provide accurateand reliable readings of the level of solids in a flooded bin. Onemethod includes dropping a weight connected to a measuring line into theflooded bin to measure the depth at which the weight stops sinking dueto contact with solid materials. This method, however, may be unreliableas the accuracy depends on properties of the solid materials and/orliquid. Loose solids may simply “swallow” the weight thereby giving afalse reading of the solid level. In addition, dropping a weighttypically requires human control or manipulation. If the liquid in theflooded bin is volatile and unsafe, this approach may present hazards tothe operator.

Another conventional measurement system includes taking sonographyreadings on the side of the bin from outside of the bin. However, thistype of method may provide inaccurate results for conical bins thatempty from the bottom. As such, the level of solids along the sides ofthe conical bin may be higher than the bin center, which could skew thereadings. Another similar measurement method is taking thermographic orinfrared readings also from the side of the bin. However, thismeasurement approach suffers from similar deficiencies as it relies uponthe temperature differences of the side of the bin. Unfortunately, thesolids level may not rise and fall significantly at the side since thesolid empties from the center of the conical bin. Another obstacle tothis method is that the temperature may fluctuate significantly due tochanges in ambient temperature (i.e., amount of sunlight, andtemperature drops from day to night). Therefore, it can be difficult totake accurate and reliable measurements using such an approach. Yetanother method of determining solid levels is to use “radar on a rope”technology. However, the dielectric between the solid material andliquid relied upon with this method may not be substantial enough toregister an accurate reading, which could prevent reliable measurements.

Accordingly, a need exists for improved apparatus and methods forreliably and accurately measuring the level of solid materials in aflooded bin.

SUMMARY OF THE INVENTION

A flooded bin measurement system is provided that generally includes asubmarine sampler for ascending and descending within a liquid of a binand for measuring the depth of fluid at the submarine sampler'slocation. According to an embodiment of the invention, the submarinesampler may ascend and descend along a vertical guide based onadjustments to its buoyancy compared with the liquid in the bin. Aspectsof the invention provide for manual and automatic control of thesubmarine sampler. Other aspects provide a bubbler system for measuringhydrostatic pressure at the submarine sampler for determining its depth.

In one embodiment, the submarine sampler includes a device having ahollow interior, an open bottom and an air supply line connected to thehollow interior. Evacuating and providing air to the hollow interior mayadjust the buoyancy of the submarine sampler to control its depth withinthe liquid. According to a further embodiment of the invention, thesubmarine sampler is fixed to a line that is connected to acounterweight at its opposite end. The counterweight and submarinesampler may be free to be moved laterally for taking measurements atvarious locations within the bin. Other features and advantages ofvarious aspects of the invention will become apparent with reference tothe following detailed description and figures.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a flooded bin measurement system according to an embodimentof the present invention;

FIG. 2A is a top view of a submarine sampler of the measurement systemof FIG. 1;

FIG. 2B is a side view of the submarine sampler of FIG. 2A;

FIG. 2C is a bottom view of the submarine sampler of FIG. 2A;

FIG. 3 illustrates a control unit of the measurement system of FIG. 1;

FIG. 4 shows a bubbler tube controller of the control unit of FIG. 3;and

FIG. 5 shows a flooded bin measurement system according to anotherembodiment of the present invention.

DETAILED DESCRIPTION

The various aspects of the invention may be embodied in various forms.The following description shows by way of illustration variousembodiments in which aspects of the invention may be practiced. It is tobe understood that other embodiments may be utilized and structural andfunctional modifications may be made without departing from the scope ofthe present invention. Referring now to FIGS. 1-4, a system 100 isgenerally shown according to an embodiment of the invention formeasuring the level of solid materials in a flooded bin via a submarinesampler 110. As shown in FIGS. 1 and 3, system 100 includes a submarinesampler 110, a weight 112, a guide 114, an air supply line 116, abubbler tube 118, a bin 120 containing a liquid 122 and solids 124, anda control unit 150 (see FIG. 3).

The submarine sampler 110 may be navigated vertically along guide 114for taking hydrostatic pressure measurements at various depths withinbin 120. As such, submarine sampler 110 moves along guide 114, which ispreferably kept taut, as it ascends and descends within bin 120. Guide114 may include a steel cable, rod or other guide member that is securedat a top end to a support (not shown), such as a bin lid, a buildingfixture or a structure overhanging bin 120, and which may be kept tautby weight 112 at its bottom end. Weight 112 is an object of sufficientmass to hold guide 114 taut and in a specified position based on factorssuch as anticipated liquid density, type of solids to be encountered andtank conditions (e.g., turbulence). As shown in FIG. 1, weight 112 maybe designed to submerge within solid materials 124. Because weight 112acts as an anchor, it may simply hang at a sufficient depth to permitnavigation of submarine sampler 110 within a desired range.Alternatively, it may reach the full depth of bin 120 and may beattached to the bottom of the bin. A hanging configuration for weight112 and guide 114 that is unattached to the bottom of the bin permitsthe weight and guide to be removed and installed along with submarinesampler 110 as desired.

Properties of guide 114, such as tensile strength, material compositionand corrosion resistance, and of weight 112, such as mass, materialcomposition, geometry and corrosion resistance, may be selectedaccording to system requirements and to ensure that the strength ofguide 114 may properly and adequately support the mass of weight 112.For example, weight 112 may include a lead anchor weighing about 50pounds that is shaped sufficiently compact to permit it to embed itselfwithin solid materials 124. Further, guide 114 may include a stainlesssteel cable having a tensile strength greater than 50 pounds (plusanticipated forces associated with retrieving the anchor from within thesolid materials as needed and/or a safety factor).

Submarine sampler 110 is adapted to ascend and descend along guide 114by adjusting its buoyancy relative to liquid 122; however, otherembodiments (not shown) may use alternative mechanisms to raise andlower the sampler unit. As shown in FIGS. 2A, 2B and 2C, submarinesampler 110 according to this embodiment includes a hollow cylinder 126having a closed top 128, an open bottom 130, an open space 132 and acenter sleeve 134. Center sleeve 134 forms a guide channel 138 throughwhich guide 114 is threaded. Center sleeve 134 may include a wearresistant material, such as high density polyethylene, that slideseasily along guide 114 and protects the rest of the cylinder againstwear due to rubbing contact with guide 114. Preferably, sleeve 134 isreplaceable to permit periodic replacement as it wears. To furtherreduce wear, guide 114 may also include a wear resistant material suchas a polyethylene coating to protect the guide 114. Maintaining such aprotective coating may further permit the attachment of air tubes 116 &118 to the guide 114. By locating the twin air tubes 116 & 118 aroundthe guide 114 (not shown), wear may be reduced on the air tubes 116 &118 as well.

Hollow cylinder 126 may be made of a rigid material, such as aluminum,stainless steel, plastic, etc., that can withstand long-term submersionin liquid 122 without significant degradation. The mass of hollowcylinder 126 should be sufficient for it to sink to the bottom of bin120 when open space 132 primarily contains liquid 122. Alternatively,hollow cylinder 126 may be relatively lightweight to permit additionalweights (not shown) to be added or removed as needed for adjusting itsmass for use with bins of various heights and/or for liquids of variousdensities.

In order to vary the buoyancy of cylinder 126 and thereby move itvertically through liquid 122 within flooded bin 120, an air supply line116 is attached to top 128. Line 116 extends from the submarine samplerto an air supply 166 (see FIG. 3), which provides compressed air asneeded to open space 132. In other configurations, line 116 may alsoconnect to the atmosphere for evacuating air from within open space 132through line 116 (e.g., if undesirable to introduce air into liquid 122when evacuating open space 132) and/or may include a plurality of lines.The addition of air into open space 132 forces liquid 122 out ofsubmarine sampler 110 via its bottom 130, which increases its buoyancyand may cause it to rise along guide 114 through liquid 122.

In order for the submarine to descend within liquid 122, air may beevacuated from open space 132 to permit liquid to enter the open spacevia bottom 130. As shown in FIGS. 2A-2C, an air release valve 144 may beattached to top 128 for permitting air to leave open space 132 asneeded. Air release valve 144 may include a solenoid valve attached to asignal wire 146, which can control operation of the valve to open andclose as needed. When air release valve 144 is opened, the buoyancy ofthe submarine sampler is reduced causing it to sink within the liquid.Air may be added and released from open space 132 as needed via airsupply line 116 and air release valve 144 to cycle the height of thesubmarine sampler within the bin.

In one variation, the air release valve 144 may be located in a remotecontrol unit (not shown) comprising a programmable logic controller. Theair release valve may also include a three-way component that allows forboth the injection and evacuation of air from open space 132. Theinjection and evacuation functions of the air release valve may becoordinated and controlled by a programmable logic controller in theremote control unit. When a user wants the submarine sample to rise, thecontroller may increase the buoyancy force of the submarine sampler byinstructing the valve to inject air through tube 116 into open space132. However, to submerge the sampler, the programmable controller may,instead, energize the valve and vent the tube 116 thereby evacuating airfrom the open space 132 and decreasing the buoyancy force. To facilitatesuch a multiple valve system, each tube 116 & 118 may further comprisetwo compartments, one for the evacuation of air and one for theinjection of air.

The depth of submarine sampler 110 within liquid 122 can be measured viabubbler tube 118 attached to the submarine sampler, as shown in FIGS.2A-2C. Bubbler tube 118 provides a relatively constant flow of air intoliquid 122, which helps to prevent the bubbler tube from clogging. Backpressure within bubbler tube 118 can be measured as desired, such aswhen submarine sampler 110 is submerged. A comparison of the backpressure measured within bubbler tube 118 with a measurement ofatmospheric pressure provides the hydrostatic pressure of liquid 122 atthe depth of the submarine sampler. Based on the known density of liquid122, a control unit (discussed later) can determine the depth of thesubmarine sampler within the liquid. Bubbler tube 118 may be attached tosubmarine sampler 110 via a flange 148 or other attachment mechanism.Bubbler tube 118 and/or air supply line 116 may be made from flexibletubing such as rubber tubing, high density polyethylene tubing,poly-vinyl chloride tubing, TEFLON tubing or plastic tubing, etc. It mayalso be made from more rigid materials, such as copper, steel, PVC orother types of pipe; however, rigid piping may need to be configuredwith a flexible material at some point to allow it to move along withvertical movement of submarine sampler 110. In the event of a clog inthe opening of bubbler tube 118, high pressure air and/or steam may beprovided to the bubbler tube to purge it.

Referring now to FIG. 3, a control unit 150 is shown according to anembodiment of the invention for controlling and measuring the depth ofsubmarine sampler 110 within bin 120. As shown, control unit 150generally includes a gas regulator 152, a data recorder/processor 154and a depth control mechanism 156. These components work in conjunctionto operate the system and to determine the level of solid materials 124within flooded bin 120. Although logically separated in this embodiment,one or more devices may perform the functions of these components.Operation of these components may be automated, such as in accordancewith program logic control instructions that control descent of thesubmarine sampler and recordation of data on a periodic basis. They mayalso be manually operable, such as via manually operable valves forraising and lowering the submarine sampler along with a manual readoutof the depth or raw hydrostatic back pressure data. A simple, manuallyoperable system may include gas regulator 152 for manual control ofsubmarine sampler buoyancy and readout of back pressure data withoutproviding the Data Recorder/Processor or Depth Control Mechanism.

In an automated configuration, the data recorder/processor 154 collectsinformation such as back pressure readings from bubbler tube 118, thechange rate of pressure reading, time stamp information for variousreadings, etc. It may also perform calculations on the data and recordinformation according to its programming and logic. Further, depthcontrol mechanism 156 may automatically control the depth of submarinesampler 110 via modifications to the buoyancy of the sampler. As such,control mechanism 156 can modify the buoyancy of the submarine samplerby instructing the gas regulator 152 to either inject or extract gasfrom the hollow space 132 of the submarine sampler.

Gas regulator 152 includes an air supply controller 158, a bubble tubecontroller 160, an evacuation valve controller 162, and a compressed airsupply line 164 connected to an air supply 166. Air supply controller158 is connected to air supply line 116 for providing air to thesubmarine sampler 110 to increase its buoyancy. Air supply controller158 may include one or more metering valves (not shown) and/or aconstant-differential relay (not shown) for providing a controlledamount of compressed air from air supply 166 to air supply line 116according to instructions from depth control mechanism 156. Evacuationvalve controller 162 is connected to signal wire 146 for providingcontrol signals to air release valve 144 on the submarine sampler. Thecontrol signals may simply include a voltage or no voltage indicationfor opening and closing a solenoid valve of release valve 144, or theymay be more elaborate control signals for partially opening releasevalve 144 a specified amount depending on the type of control signal.Bubbler tube controller 160 is connected to bubbler tube 118 forproviding a constant rate of air to bubbler tube 118 from air supply 166and for sensing the back pressure of air within bubbler tube 118. Asshown in FIG. 4, bubbler tube controller 160 may include aconstant-differential relay 168 and differential pressure celltransmitter 170, which receives a constant supply of metered air fromconstant-differential relay 168. Constant-differential relay 168 may bean airflow controller, as is known in the art, such as a MOORE 62VNAConstant-Differential Relay. Constant-differential relay 168 receivescompressed air at varying pressure and flow rates and provides air at aconstant output pressure and flow rate to bubbler tube 118.

Cell/Transmitter 170 is attached to bubbler tube 118 and senses theoverall pressure in the bubbler tube, which changes according tohydrostatic pressure at the submarine sampler 110 based on its depthwithin liquid 122. As the depth of the submarine sampler changes, thehydrostatic pressure at the submarine sampler changes causing acorresponding change in back pressure of air within bubbler tube 118.Cell/transmitter 170 senses the back pressure in bubbler tube 118 andcompares it with atmospheric pressure to determine the pressuredifferential. This information is transmitted to data recorder/processor154 (see FIG. 3), which records and processes the data. The pressuredifferential information may also be read directly from cell/transmitter170 by an operator. Also, cell/transmitter 170 can be set up to transmitthis information to a network, remote recorder, remote controller, etc.(not shown) located apart from the cell/transmitter.

Differential pressure cell transmitter 170 may be an electronicdifferential pressure cell transmitter, such as a FOXBORO IDP10Intelligent d/p Cell Transmitter for differential pressure measurement.Cell/transmitter 170 calculates the hydrostatic pressure around themouth of bubbler tube 118 using a known specific gravity for liquid 122by comparing the atmospheric pressure and bubbler tube back pressureaccording to the following formula: H=ΔP/Sg, where ΔP=the differencebetween the bubbler tube pressure and the atmospheric pressure, andSg=specific gravity of fluid 122. The vertical level of liquid 122disposed above the mouth of bubbler tube 118 at the submarine samplercan be determined based on the hydrostatic pressure, H, around the mouthof the bubbler tube.

Constant-differential relay 168 receives pressurized air, which itmeters to provide a substantially continuous supply of metered air tobubbler tube 118. The substantially constant flow of air acts to purgeany condensation from bubbler tube 118. By providing metered air,fluctuations in the flow of purge air are reduced or eliminated, whichreduces sensor inaccuracies related to noise from such fluctuations.Bubbler tube controller 160 is preferably mounted above bubbler tube118, which reduces the amount of condensation that can collect in thebubbler tube.

Depth control mechanism 156 may automatically control the depth ofsubmarine sampler 110 via modifications to its buoyancy in accordancewith programmed instructions. For instance, depth control mechanism 156may be set up to sample the level of solids in bin 122 on a periodicbasis. Control mechanism 156 can modify the buoyancy of the submarinesampler by instructing the gas regulator 152 to either inject or extractgas from the submarine sampler. Additionally, control mechanism 156 maybe used to control the amount of time allowed for each measurement, thetime interval between each back pressure reading and/or the timeinterval between each gas injection/extraction.

Control mechanism 156 may further include logic to control the ascentand descent of the submarine sampler 110 to provide more accurateresults and to reduce the possibility of the submarine sampler becomingpartially buried within the solids material 124. For instance, controlmechanism 156 may incrementally adjust the amount of air within openspace 132 to slowly raise or lower submarine sampler 110 until backpressure readings stabilize. Once the readings stabilize, the controlmechanism may cause the depth of the submarine sampler to be calculatedand recorded. Alternatively, control mechanism 156 may wait a givenperiod from the time air release valve 144 is opened to evacuate air inorder to permit sufficient time for submarine sampler 110 to completelydescend before calculating and recording its depth.

Referring now to FIG. 5, a system 200 is generally shown according toanother embodiment of the invention for measuring the level of solidmaterials in a flooded bin via a submarine sampler 110. System 200generally includes the aspects and preferences of system 100, except asdiscussed below. As shown, system 200 generally includes submarinesampler 110, air supply line 116, bubbler tube 118, bin 120 containingliquid 122 and solids 124, and control unit 150, which are common tosystem 100. As illustrated, bin 120 may be a conical bin having a drain284 at its bottom or a bin of another configuration, such as therectangular bin of FIG. 1 or another shape. System 200 also includes apivot member 280, a counterweight 282, a line 286, and optionallyadjustment weights 288.

System 200 provides a flexible system that permits submarine sampler 110to easily be withdrawn from bin 120 and allows the submarine sampler tomeasure the depth of solid materials 124 at various locations within bin120 as desired. System 200 may be used without a weight that can becomeembedded within the solid materials 124 and become difficult toretrieve, such as weight 112 of FIG. 1. Preferably, counterweight 282substantially counteracts the mass of submarine sampler 110 such thatthe submarine sampler has sufficient mass to sink relatively gently tothe bottom of bin 120 without embedding itself within solid materials124 when air is evacuated from within the submarine sampler, and yetprovides sufficient force to raise the submarine sampler from the bottomof the bin when it is filled with air. Adjustment weights 288 may beadded to submarine sampler 110 to tune the mass differential between thesubmarine sampler and the counterweight, which may be appropriate foradjusting the system for use with liquids of various densities, bins ofvarious depths, and/or for various process conditions (e.g., turbulence,drainage, rotation, etc. within the bin).

Line 286 may be a steel cable or other flexible member designed forrepeated measurements and submersion within liquid 120. For example, astainless steel cable or a plastic coated carbon steel cable may beappropriate. Pivot member 280 may be a pulley or other pivoting devicethat can permit a counteracting force to oppose motion of submarinesampler 110 as it ascends and descends within liquid 122. In theembodiment of FIG. 5, pivot member 280 is a pulley that rotatesgenerally horizontally along an axis. Preferably, pulley 280 alsorotates generally vertically along an axis, is translatable along agenerally horizontal axis, and/or is movable between support locationsto permit submarine sampler 110 to be disposed in various locationswithin bin 120 as desired. Optionally, submarine sampler 110 may bemovable along with pivot member 280 to permit it to be used withmultiple bins (not shown). Pivot member 280 may be attached to abuilding fixture, a portion of the bin, a portable support designed foruse with system 200, or another support structure. Counterweight 282 isan object of sufficient mass to preferably keep line 286 taut whilesubmarine sampler 110 ascends and descends within bin 120. As withsubmarine sampler 110, adjustment weight 288 should be designed to besubmerged within liquid 122 on a repeated or long-term basis.

Suppose as an example that counterweight 282 weighs about 30 pounds,submarine sampler 110 weighs about 20 pounds and adjustment weights 288are about 20 pounds. Discounting the mass of line 286, the massdifferential is about 10 pounds at the submarine sampler, whichencourages it to sink within bin 120 when air is evacuated from it.However, submarine sampler 110 will sink with less downward force (10pounds force) than if its mass were not counteracted by counterweight282 (20 pounds of force without counterweight and adjustment weights).Hence, submarine sampler 110 can be adjusted to impact solid materials124 with less force than without the counterweight, which may reduce thelikelihood of the submarine sampler becoming embedded within the solidmaterials. Suppose that when submarine sampler 110 is filled with air,the air displaces about 20 pounds of liquid 122 from within thesubmarine sampler. As such, about 10 pounds of force will encourage thesubmarine sampler to rise to the surface of the liquid when filled withair.

Otherwise, system 200 generally operates in much the same way as system100. In order to raise submarine sampler 110, air may be pumped intoopen space 132 through air supply line 116. To encourage submarinesampler 110 to sink, air may be released from open space 132 via airrelease valve 144. A control mechanism can reduce the amount of humancontrol necessary in the process. For instance, the pumping of airthrough air supply line 116 may be controlled via control unit 150described along with FIGS. 3 and 4.

While the present invention has been described in connection with theillustrated embodiments, it will be appreciated and understood thatmodifications may be made without departing from the true spirit andscope of the invention. In particular, the invention applies to a widevariety of measurement systems and methods. For instance, rather thanusing a hollow cylinder for the submarine sampler according to thedisclosed embodiments, other shapes and designs for submarine samplersmay be used. As an example, an adjustable volume bladder may be attachedto solid mass to change the overall buoyancy of the combination and tothereby cause the mass to ascend and descend within a flooded bin basedon the volume of the bladder. In another example, instead of a bubblertube measurement system, a linear distance measurement device may beattached to line 286 to measure its movement from a set point as thesubmarine sampler rises and lowers for determining the depth of thesubmarine sampler. In another example, rotations of pulley 280 may bemeasured to determine the depth of the submarine sampler from a setpoint as it ascends and descends within the bin. Moreover, methods andsystems of the present invention may be used to accomplish a variety ofother tasks. In one example, the submarine sampler may be used to takesamples of a liquid or solid at a given depth in a container. In anotherexample, the sampler may take temperature readings or disperse achemical at a given level and/or time in a particular process.Additionally, a variety of systems and methods may be used to measurepressure in a bubble tube. Further, methods and systems of the presentinvention do not need to include all aspects and features disclosed inthe embodiments discussed herein.

1. A device for measuring a depth of a liquid, comprising: a line havinga first and second end; a sampler connected to the first end of theline, wherein a depth of the sampler corresponds to the depth of theliquid; an air supply system fluidly communicating with the sampler tovary buoyancy of the sampler; a bubbler tube receiving an air flow fromthe air supply and emitting the air flow when immersed in the liquid; aregulator measuring back pressure exerted by the liquid in the bubblertube when the air flow is emitted from the bubbler tube; a pivot memberin contact with the line; and a counterweight connected to the secondend of the line; wherein, the depth of the sampler is measured via thebubbler tube.
 2. The device of claim 1, in which the sampler comprises aclosed top and an open bottom.
 3. The device of claim 2, in which theair supply system comprises a valve allowing egression of air from thesampler.
 4. The device of claim 2, in which the air supply systemcomprises a valve allowing injection of air into the sampler andevacuation of air from the sampler.
 5. The device of claim 1, in whichthe air supply system comprises an air supply line deliveringpressurized air to the sampler.
 6. The device of claim 5, in which theregulator comprises a bubbler tube controller controlling a flow of airfrom the air supply system to the bubbler tube, an air supply controllercontrolling air flow from the air supply system to the air supply line,and an evacuation valve controller controlling egression of air from thesampler.
 7. The device of claim 6, further comprising a depth controlmechanism configured for electrical communication with the air supplycontroller and the evacuation valve controller.
 8. The device of claim1, further comprising a data recorder recording back pressure readingsfrom the regulator.
 9. A bin in combination with the device of claim 1,the bin containing the liquid and a deposit of solids at a bottomthereof.